Gang members involved in knife crime should be seen as "moronic" rather than as glamorous figures like Shakespeare's Mercutio, Boris Johnson said today.

The London mayor used a reference to the character from Romeo and Juliet when explaining to MPs why it was important that knife crime should not be glamorised.

Giving evidence to the Commons home affairs committee, Johnson said: "My heart sinks when I hear and read of some of the language used to describe some of the victims of knife crime by other members of gangs.

"This stuff about 'You were a good soldier' or 'Fallen soldier'; we do need as repeatedly as possible as a society to detonate the myth that there is anything romantic or glamorous about these tragic episodes."

He added: "We need to deglamorise knife crime and make clear to people that this is moronic and wasteful.

"This is not the death of Mercutio taking place on the streets of London."

Asked to explain the reference to Romeo and Juliet, Johnson, who is often fond of quoting from the classics, said: "It is a guy called Mercutio who is killed in a gang fight.

"It is worth studying the text because it does teach you something about the bogus atmosphere of glamour that can surround these gangs and the sort of romantic, sentimental feelings that can start to occur with knife crime and gang culture generally."

Johnson said figures respected by young people, such as Manchester United footballer Rio Ferdinand, should be recruited to "speak against the evils of carrying knives".

He said he supported proposals to make casualty unit staff report patients with knife wounds, as they do with gun crime victims.

He went on: "I think we should look at making sure that hospitals are similarly useful in dealing with knife crime by reporting knife wounds.

"There is an argument to be had about whether or not this would deter people from seeking medical attention in the case of knife wounds.

"We need to look at the possible adverse impact that policy might have on those that have been wounded."

During the hearing, which was part of an investigation into policing in the 21st century, the chairman, Keith Vaz, announced that the committee would be conducting a new inquiry specifically into knife crime.

Johnson also refused to say whether he was in favour of the Metropolitan police commissioner, Sir Ian Blair, having his contract extended when it expires in 2010.

The mayor said that he did not want to discuss "personnel issues" with the committee.